mjcphoto

in low light i have found the expanded af works better if spot focus is giving trouble you know the mode with the 8 af assist points enabled. this is on a 5d mk3 though also has anyone else noticed how good at focusing the 16-35 f2.8L ii is in very ow light?its very snappy

Thanks, I'll try that out! So, did you notice it had trouble in low light with spot focus?

This is known! Spot AF is slower in low light than other modes period I believe AND in the 5D3 manual on page 77 (also somewhere in 1DX since same AF system) it states

With Single-point Spot AF, focusing with the Speedlite's AF-assist beam may be difficultIf the camera cannot focus with the EOS-dedicated Speedlite's AF-assist beam, set the AF area selection mode to SINGLE-point AF (Manual selection) and select the center AF point to focus.

EDIT: It does take longer. In the 1DX AF Setting Guidebook on page 27 it says

As [Single-point Spot AF] only focuses on one very small area, it is not really suited to capturing fast moving subjects when set to AI Servo AF and may take longer to focus than other AF area selection modes.

Yeah, I have my focus grid set up to show just the points that work with 2.8F lenses and wider. So, focus is accurate when using those points.

I almost always manually select my point and I'm in one shot mode. Over the years I've trained myself to focus on contrasting clothing or lighter parts of my subject when in low light situations. Like I said, the 1D Mark3, no problem....the 1DX...in low light...it's having problems!

When it was acquiring quickly in low light, it would look great on the screen after taking the shot. But, I have the zoom set to zoom at 100% to the focus point used so I can check and I was missing many that were supposedly in focus (and yes, with a Canon flash / 600 or 580EX, assist beam, under the metered light, etc).

A little frustrating b/c I thought I found the holy grail of cameras!!! I have a work around (MK3 for the low lit reception halls), but after waiting years for this camera, I feel like I should be able to use it in all situations. You know???

I fully understand... As mentioned before, perhaps check what AF scenario you are set at... If you get good focus in good light but bad, and AF assist doesn't help much, that would be tough... with your telephotos, I would assume you are at some distance from your subject you are photographing, am I correct? I would play with expansion modes, that's what I use... with single spot if your subject move off it, or if the camera perceives it to do so, then it could start hunting for a new AF, especially since it doesn't have any are to track the movement... AF expansion could give you that little bit of leadway should the subject move. If that doesn't help, and the AF scenario is about right, then feel free to call Canon or send it in. If you have CPS, you could call their hotline number and they can talk you through all scenarios and see if they can figure it out. Hope that helps.

in low light i have found the expanded af works better if spot focus is giving trouble you know the mode with the 8 af assist points enabled. this is on a 5d mk3 though also has anyone else noticed how good at focusing the 16-35 f2.8L ii is in very ow light?its very snappy

Thanks, I'll try that out! So, did you notice it had trouble in low light with spot focus?

yes i did ive always only used spot focus in the past so now im still learning this new af system i think once i fully understand it that it will be amazing, i love the on demand ai servo with the dof preview button too one addition to this that woud be nice would be to preconfigure a particular af mode to be linked to it so you can be in singe shoot spot af and press the button and get ai servo and say expanded or zone af

Logged

APS-H Fanboy

Richard Lane

...i love the on demand ai servo with the dof preview button too one addition to this that woud be nice would be to preconfigure a particular af mode to be linked to it so you can be in singe shoot spot af and press the button and get ai servo and say expanded or zone af

In low light I definitely never try to spot focus, ever, in any situation. I've found it just doesn't make that much difference in most, not all, but most, situations. I've had fantastic luck with the 5D Mark III in very low light, I just haven't tried the 1DX there yet.

Logged

2 x 1DXB1G, MAC, GLIAC

mjcphoto

Thanks guys! I just played around with expansion and it seems like it does the trick just fine!

I guess I was so used to single point selection with my previous 1D's (and it worked all the time), that I never went there. I'm also a control freak (I'm sure many others here are as well) and love control of my point. That said, looks like I'll have even more control in using expansion in lower light or backlit situations indoors as well. Thanks so much!

I love that you can pull up a Custom Function within the modes. Dig the fact that it remembers where your focus point was when you go from landscape to portrait...makes formals a breeze! Okay, it is the holy grail!!!

Dig the fact that it remembers where your focus point was when you go from landscape to portrait...makes formals a breeze! Okay, it is the holy grail!!!

Hi Michael,

I'm glad you found a solution, I just wanted to make sure that you're aware of the Auto-Focus Micro-Adjustment bug, which occurs when you have your AF point linked to portrait or landscape orientation, and then the AFMA settings for your lens doesn't take affect. Since you said that you locked focus on a few shots and they were still OOF, I just wanted to make sure that you were aware of the bug.

Thanks guys! I just played around with expansion and it seems like it does the trick just fine!

I guess I was so used to single point selection with my previous 1D's (and it worked all the time), that I never went there. I'm also a control freak (I'm sure many others here are as well) and love control of my point. That said, looks like I'll have even more control in using expansion in lower light or backlit situations indoors as well. Thanks so much!

I love that you can pull up a Custom Function within the modes. Dig the fact that it remembers where your focus point was when you go from landscape to portrait...makes formals a breeze! Okay, it is the holy grail!!!

The AF points are smaller due to their being 61 of them, so using the AF assist points makes a bit of sense. I had trouble with my 5D MK III in low light, that might fix it as well.

Thanks guys! I just played around with expansion and it seems like it does the trick just fine!

I guess I was so used to single point selection with my previous 1D's (and it worked all the time), that I never went there. I'm also a control freak (I'm sure many others here are as well) and love control of my point. That said, looks like I'll have even more control in using expansion in lower light or backlit situations indoors as well. Thanks so much!

I love that you can pull up a Custom Function within the modes. Dig the fact that it remembers where your focus point was when you go from landscape to portrait...makes formals a breeze! Okay, it is the holy grail!!!

Haha it makes me feel good to not be the only one that went through this!

You must have set the 1d X up wrong, because even if you have a magic 7d and 1d3, the X is still way better. But to use that supersmall spot af will be a poor choice for lowlight and without expansion points the iTR tracking doesn't work. I find the 1d X to be without question the best camera on every level ever produced. I shoot in 12800 f1,4 light with 1/80s and the exposure and af works fantastic!

You must have set the 1d X up wrong, because even if you have a magic 7d and 1d3, the X is still way better. But to use that supersmall spot af will be a poor choice for lowlight and without expansion points the iTR tracking doesn't work. I find the 1d X to be without question the best camera on every level ever produced. I shoot in 12800 f1,4 light with 1/80s and the exposure and af works fantastic!

+1

I just had some professional 8 x 10 prints done with metallic luster with a 1DX and they look just as good as any 22mp photos I have taken with the 5D Mark III.

mjcphoto

You must have set the 1d X up wrong, because even if you have a magic 7d and 1d3, the X is still way better. But to use that supersmall spot af will be a poor choice for lowlight and without expansion points the iTR tracking doesn't work. I find the 1d X to be without question the best camera on every level ever produced. I shoot in 12800 f1,4 light with 1/80s and the exposure and af works fantastic!

Actually, I set up a custom function group from the start to have the ability to turn and capture something on the fly (love that). And the standard back button focus lock using the asterisk like on all my other 1D bodies. I also set up the focusing points to just show the points that work best with F2.8 lenses and wider. So it's pretty dialed in.

I suppose I was just used to my 1D MKIII working in 1 point spot mode in extremely low light and nailing it. I reckon, going to a full frame makes things a bit difference since the sensor is much larger. The expansion points make a whole lot of sense now. Especially after playing around with it last night recreating the circumstances I was faced with at the wedding. Looks like it also helps having expansion on when shooting into extreme backlit situations. This camera totally rocks!

Thanks again everyone! I'm digging the forum even more than the camera

Thanks guys! I just played around with expansion and it seems like it does the trick just fine!

I guess I was so used to single point selection with my previous 1D's (and it worked all the time), that I never went there. I'm also a control freak (I'm sure many others here are as well) and love control of my point. That said, looks like I'll have even more control in using expansion in lower light or backlit situations indoors as well. Thanks so much!

I love that you can pull up a Custom Function within the modes. Dig the fact that it remembers where your focus point was when you go from landscape to portrait...makes formals a breeze! Okay, it is the holy grail!!!

Haha it makes me feel good to not be the only one that went through this!

Yeah, just when you thought you knew it all...there is always something more to learn. thanks again!!!!!!